Crossing wet or dry gaps being principally but not exclusively one of the main fields of activity of military engineering, the present invention will mainly concern the construction of military amphibious vehicles which need to be configured so as to be capable of enabling the crossing of vehicles, particularly heavy military vehicles, for example, up to 110 metric tons, but also personnel with their equipment. Furthermore, it is desirable for the vehicle equipped with the invention to be transportable by air so that it can be moved quickly from one region to another, at least by airplane and preferably also by helicopter.
In order to meet these different expectations, the amphibious vehicle must be configured so that it can be used satisfactorily and as much as possible equivalently on water as well as on land. Furthermore, it must be capable, without outside help, of crossing the intermediate region between the water and the ground and must in particular be capable of adapting to the morphology of the banks or shores. Finally, without being exhaustive as to the characteristics required of an amphibious vehicle to which the vehicle of the invention responds, the amphibious vehicle must be capable of being used alone or in combination with a number of other vehicles of the same design in order to form a floating bridge.
In order to be able to meet the requirements of road travel as well as of positioning in the form of a floating bridge, the elements necessary for forming a bridge, such as caissons, floats and ramps, have in the past been arranged in different manners on a vehicle in the form of a self-propelled rolling base. Among the different attempted configurations is also that of a turning arrangement according to which the group of caissons, ramps and possibly floats forms a unit mounted so as to pivot on the rolling base. According to this design, when the vehicle is launched, the longitudinal axis of the rolling base is oriented approximately parallel to the shore of the river or lake to be crossed. And when the vehicle is in position, the group of elements forming the bridge is turned in one direction or the other approximately 90° around a vertical axis.
However, the diversity of the morphologies of the wet or dry gaps to be crossed requires the ability to adapt the arrangement of the elements forming a floating bridge. In this sense, it has proven disadvantageous to have to turn the group of elements in the form of a single unit.